Nutmeg toxicity: just when you thought it was safe to go back to the eggnog bowl

April 24, 2011, 4:56 pm

Skip the methods and results sections of this paper and turn directly to the discussion, which is the best short treatment of nutmeg toxicity in the medical literature. (I recently reviewed that literature for an Emergency Medicine Newscolumn that should be posted in the next week or so.) The study itself conducted a retrospective chart review of the California Poison Control System electronic database for cases of isolated nutmeg exposure during the years 1997 – 2008. The authors identified 119 single-substance exposures, collected descriptive data, and compared intentional recreational abuse (86 cases) with unintentional exposures (33 cases). One question they don’t answer: how does one get an unintentional exposure to a toxic amount of nutmeg? Too much eggnog?

Nutmeg, the seed of the Myristica fragrans tree, has been used medicinally for over a millennium, and abused for purported hallucinogenic and psychotropic effects at least since the mid-twentieth century. In his Autobiography, Malcolm X talks about using nutmeg in prison to get high, and reports that “a penny matchbox full of nutmeg had the kick of three or four reefers”. (Although as we now know from Manning Marable’s new book, the Autobiography — written with Alex Haley and completed after Malcolm’s assassination — was exaggerated and inaccurate in many aspects.) By all accounts, nutmeg produces a very unpleasant trip and those who ingest large doses are unlikely to do so again.

Some of the points made in the authors’ discussion:

There is no clear toxidrome associated with nutmeg toxicity.

The most frequent signs and symptoms in this case series were tachycardia, emesis, and agitation.

Although the exact mechanism that could produce possible psychotropic effects in humans is not known, animal studies suggest that constituents of the seed may be metabolized into the hallucinogenic stimulant MMDA, or act as a monoamine oxidase inhibitor.

One other thing I like about this paper is that it doesn’t accept the myth — repeated in numerous previous articles and textbook chapters — that nutmeg toxicity caused the death of a child in the 1800s. As the authors note, the report of that case (The Medical Record 1887;32:624) describes an 8-year-old boy who ingested two nutmeg seeds and became obtunded. The physician who responded to the scene administered an emetic and “diffusable stimulants”, after which the child vomited profusely and became comatose. This treatment was followed by “hypodermic injections of brandy, ammonia, and small doses of sulphate of atropia”. The boy died the next morning. As the authors remark, “one may question whether the treatment was more toxic than the ingestion”.